North and South Stradbroke Islands were initially joined and separated in 1895 after a violent storm to give the passage known as Jumpinpin. It is probable that the former Stradbroke Island joined the Spit at Southport, as neither Cook (in 1770) nor Flinders (in 1799) recorded the passage now known as The Southport Bar. It is also possible that Moreton Island joined Stradbroke Island in recent times, as Cook (in 1770) did not note the South Passage Bar, Flingers (in 1799) being the first to record it. Erosion of the southern end of Moreton Island is still gradually widening the gap between the two islands.
The High Dunes
Most nutrients have leached from the high dunes by rain waters and the soils are thus infertile in the agricultural sense. These dunes, however, generally support tall open forests, dominated by eucalypts, with a well- developed understory of grasses and shrubs. The more common species of eucalypts include blue gum (Eucalyptus tereticornis); scribbly gum (E. signata); pink and red bloodwoods (E. intermedia and E. gummifera) and blackbutt (E. pilularis). Other trees of the open forests include the smooth-barked apple (Angophora costata); the she-oaks (Casuarina littoralis and C. torulosa); the cypress-pines (Callitris columellaris and C. rhomboidea). Smaller trees and shrubs include several wattles or acacias such as the black wattle (Acacia cunninghamii); sweet wattle (A. suaveolens), prickly moses (A. ulicofolia) and the wallum and coastal banksias (Banksia aemula and B. integrifolia). These banksias and some of the eucalypts attract many nectar eating birds and insects when flowering.
Shrubs of the understory include May-bushes or Tea-trees (Leptospernum) and baeckea species with masses of small white flowers; geebungs (Persoonia) species with yellow or cream flowers; wedding bush (Ricinocarpus pinifolius) which can provide a spectacular spring show with masses of white flowers; grass-trees or blackboys (Zanthorrhoea Johnsonii) with striking spear-like flowering spikes which are attractive to nectar-eating birds and insects, and the blueberry ashes (Elaeocarpus obovatus and E. reticulatus ).
Many smaller flowering shrubs and creepers also occur, including the pink flowering boronia (Boronia rosmarinifolia); eggs & bacon (Dillwynia floribunda); the yellow pea (Phyllota phylicoides) and false sarsparilla (Hardenbergia violacea). The well known bracken fern (Pteridium esculentum) is widespread, as is the matrush (Lomandra longifolia).
Mangroves conspicuously occupy the inter-tidal zone along the western side of the island, ranging from isolated trees to extensive forests in the south and in Swan Bay. The common and dominant species is the grey mangrove (Avicennia marina), but stilted mangrove (Rhizophora stylosa), large-leafed mangrove (Bruguiera gymnorrhiza), spurred mangrove (Ceriops tagal), river mangrove (Aegiceras corniculatum), and the milky- sapped blind-your-eye (Exoecaria agallocha) are all well distributed. Areas of muddy sand adjacent to the mangroves support several species of seagrass, of which Zostera capricornia) the most abundant.
Since the closure of the whaling station on Moreton Island in 1962, the population of the humpback whale (Megaptera novae-angliae) has increased slowly and they can now be seen annually from vantage points at Point Lookout during the north-bound migration in June and July and during the south-bound migration in September and October. Dolphins are common, both offshore and in Moreton Bay. The bottle-nosed dolphin (Tursiops aduncus) is the most plentiful, but the spotted dolphin (Sousa lentiginosa) also occurs. Dugong (Dugong dugon) feed on the seagrasses of Moreton Bay and may occasionally be seen as they come up to breathe.
Almost all visitors to North Stradbroke Island arrive by ferry and a good variety of birds can be seen on Moreton Bay during the crossing. These include the pied cormorant (Phalacrocorax varius) and the smaller little pied cormorant (P. melanoleucos) which can be seen perched on the navigation guides or fishing. Pelicans (Pelecanus conspicillatus); black swan (Cygnus atratus) which often occurs in a large loose flock of 200 or more out from Cleveland; the well known silver gull (Larus novae- hollandiae) with red legs and bill; crested tern (Sterna bergii) which is about the same size as a silver gull but with black cap and yellow bill; little tern (Sterna albifrons) which is much smaller than the crested tern, and perhaps the caspian tern (Hydroprogne caspia), the largest of our terns, with a large red bill and black cap.
Four raptors may often be seen on Moreton Bay or along the edges of Stradbroke Island. These are the brahminy kite (Haliastur indus), with rich reddish-brown back and wings and contrasting white head; white- bellied sea-eagle (Haliaeetus leucogaster), grey above, white below and often seen soaring with broad upswept wings; whistling kite (Haliastur sphenurus), rather dingy looking and characterized by a loud whistling call “pee-oar-wh-wh-wh-wh-wh-wh-wh”; and the osprey (Pandion haliaetus), with white head, dark eyestripe and brown back and tail, perhaps diving into the water to capture a fish or maybe eating a fish whilst perched.
At low tide mixed flocks of waders feed on the sand and mud banks north of Dunwich and at high tide they congregate on exposed sand spits. Migratory waders are usually seen in their drab brown and grey non- breeding plumages during our summer months. The largest of these is the eastern curlew (Numenius madagascariensis) with a very long down- curved bill. The whimbrel (N. phaeopus) is smaller than the curlew and its down-curved bill is proportionally shorter. The bar-tailed godwit (Limosa Lapponica) is similar in size to the whimbrel but has an almost straight bill which is slightly up-turned. Smaller waders include the lesser golden plover (Pluvialis dominica), plumpish, with a short bill, grey-brown with yellowish speckles; greenshank (Tringa nebularia) greyish above, white under, greenish legs and a long, thin bill; and the black and white black- winged stilt (Himantopus himantopus) with very long, thin, pink legs.
Several species of birds are usually found only in mangroves or in adjacent areas. These include the striated or mangrove heron (Butorides striatus), a squat-crouching grey or brown heron; mangrove kingfisher (Halicyon chloris), blue-green on back with a white breast and heavy black bill; mangrove warbler or gerygone (Gerygone levigaster), a very small bird with a brown back, white underpants, white eyebrow and red eye, (its mournful call is heard more often than the bird is seen); and the mangrove honeyeater (Lichenostomus versicolor), a medium-sized honeyeater with a series of strong melodious calls.
Larger species which are likely to be seen on the beaches, in swamps or in open grass-lands include the familiar masked plover or lapwing (Vanellus miles) with black cap, yellow face wattles and a raucous call; sacred or white ibis (Threskiornis aethiopica), a white ibis with a black head; straw-necked ibis (Threskiornis spinicollis), a black and white ibis with yellow plumes; Royal spoonbill (Platalea regia), white, with black spatulate bill; and white-faced heron (Andea novae-hollandiae), a blue- grey heron with a white face.
The familiar gannet (Morus serrator) can usually be seen from Point Lookout, especially in winter, while the wedge-tailed shearwater or muttonbird (Puffinus pacificus), which has a small breeding colony at Point Lookout, can be seen during the summer banking and gliding close to the waves. Many other sea-birds have been recorded off Point Lookout, including albatrosses, petrels, shearwaters, frigatebirds, boobies, skuas and terns.
Nectar-eating species are a conspicuous part of the avifauna of North Stradbroke Island. Most conspicuous are the well-known rainbow lorikeet (Trichoglossus haematodus) and the scaly-breasted lorikeet (T. chlorolepidotus) which congregate in noisy, colourful flocks when the banksias and eucalypts are in flower. Many honeyeaters are conspicuous in the forests and heaths, including the noisy friarbird or leatherhead (Philemon corniculatus), which is characterized by a bare black head and upright knob on bill and is made conspicuous by its loud, harsh but pleasant calls; little wattlebird (Anthochaera chrysoptera), with an untidy streaked appearance and a raucous, chuckling series of calls, is often found in banksias; the familiar noisy miner or mickey (Manorina melanocephala), a grey-brown and yellow honeyeater forming sociable, aggressive flocks; white-cheeked honeyeater (Phylidonyris nigra), a distinctive-black and white bird often found in the banksia heathlands; brown honeyeater (Lichmera indistincta), a small olive-brown bird without distinctive markings but with a rich, varied call; and the scarlet honeyeater (Myzomela sarguinolenta), a tiny bird, dull brown if female, but having a brilliant scarlet head and back if male.
Other well distributed and common birds are the kookaburra (Dacelo novaeguineae); rainbow bee-eater (Merops ornatus), a beautiful iridescent blue-green and bronze bird which nests in a tunnel dug in the ground; dollar-bird (Eurystomus orientalis) (summer), a dumpy, dark blue-green bird with white, round patches on the wings seen in flight; the familiar black-faced cuckoo-shrike or blue jay (Coracina novaehollandiae), a blue- grey bird with black face and throat and a characteristic habit of shuffling its wings on alighting; rufous whistler (Pachycephala rufiventris), the male easily recognized by grey back, and black breast band separating the white throat from the rufous breast and belly; figbird (Sphecotheres viridis), a stocky species, brown above and streaked below if female, and with red skin around the eye if male, often found in sociable flocks feeding on figs or other fruiting trees; spangled drongo (Dicrurus hottentotus), glossy black with a characteristic fish tail and red eye.
Finally mention should be made of the familiar black and white birds which are so common throughout much of eastern Australia; willie wagtail (Rhipidura leucophrys); magpie-lark or pee-wee (Grallina cyanoleuca); pied butcher bird (Cracticus nigrogularis); Australian magpie (Gymnorhina tibicen); pied currawong (Strepera graculina); and the all- black torresian crow (Corvius orru).
The birds listed are but a small fraction of the 260 species which have been recorded for North Stradbroke Island but some species are vagrants and are unlikely to be seen.
About 16 species of snakes occur on North Stradbroke Island. Species most likely to be encountered include the carpet python (Python spilotes); green tree-snake (Dendralaphis punctulatus); and the red-bellied black snake (Pseudechis porphyriacus). The death adder (Acanthophis antarcticus) is well distributed but is uncommon. Several species of sea snakes also occur.
Larger lizards which may be encountered include the sand monitor (Vanarus gouldii); lace monitor (V. varius) and bearded dragon (Amphibolurus barbatus), but many species of skinks are also present.
The long-necked tortoise (Chelodina longicollis) frequents permanent swamps and lakes and is the only land tortoise present. Green turtles (Chelonia mydas); and loggerhead turtles (Caretta caretta) can sometimes be seen in Moreton Bay or in the off-shore waters near Point Lookout.